From mboxrd@z Thu Jan 1 00:00:00 1970 From: sukadev@us.ibm.com Subject: Re: 2.6.21-rc4-mm1: freezing of processes broken Date: Tue, 20 Mar 2007 19:47:01 -0700 Message-ID: <20070321024701.GC13436@us.ibm.com> References: <20070319205623.299d0378.akpm@linux-foundation.org> <46004B02.7020407@gmail.com> <200703202206.38168.rjw@sisk.pl> <200703210149.33240.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: "Eric W. Biederman" Cc: Jiri Slaby , Pavel Machek , Andrew Morton , linux-pm@lists.osdl.org, linux-kernel@vger.kernel.org, Oleg Nesterov List-Id: linux-pm@vger.kernel.org Eric W. Biederman [ebiederm@xmission.com] wrote: | "Rafael J. Wysocki" writes: | = | > On Tuesday, 20 March 2007 22:06, Rafael J. Wysocki wrote: | >> On Tuesday, 20 March 2007 21:58, Jiri Slaby wrote: | >> > Rafael J. Wysocki napsal(a): | >> > > Actually, the problem is 100% reproducible on my system too and I = doubt | > it's | >> > > caused by the recent freezer patches. | >> > = | >> > I don't know what exactly do you mean by recent, but 2.6.21-rc3-mm2 = works | >> > for me. | >> = | >> Thanks for the confirmation. | >> = | >> The patches I was talking about had already been in 2.6.21-rc3-mm2, so= the | >> reason of this failure must be different. | > | > Bisection shows that the freezing of processes has been broken by one o= f the | > patches: | > | > remove-the-likelypid-check-in-copy_process.patch | = | Grr. Oleg's review of remove-the-likelypid-check-in-copy-process | showed it to be questionable (and it was just an optimization) | so we can get rid of that one easily. = | = | Although all it did that was really questionable was add | the idle process to the global process list and bump a process | count when we forked the idle process. Not dramatically dangerous | things. | = | > use-task_pgrp-task_session-in-copy_process.patch | = | As I recall that patch was pretty trivial, and shouldn't have | anything to do with the freezer. The process freezer doesn't care | about pids does it? Yes. I think this one is trivial too. Here is the effective change in copy_process(): - attach_pid(p, PIDTYPE_PGID, find_pid(pgid)); - attach_pid(p, PIDTYPE_SID, find_pid(sid)); + attach_pid(p, PIDTYPE_PGID, task_pgrp(current)); + attach_pid(p, PIDTYPE_SID, task_session(current)); | = | Eric